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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/kernel/power/swap.c
4 *
5 * This file provides functions for reading the suspend image from
6 * and writing it to a swap partition.
7 *
8 * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
9 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
10 * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
11 */
12
13#define pr_fmt(fmt) "PM: " fmt
14
15#include <linux/module.h>
16#include <linux/file.h>
17#include <linux/delay.h>
18#include <linux/bitops.h>
19#include <linux/genhd.h>
20#include <linux/device.h>
21#include <linux/bio.h>
22#include <linux/blkdev.h>
23#include <linux/swap.h>
24#include <linux/swapops.h>
25#include <linux/pm.h>
26#include <linux/slab.h>
27#include <linux/lzo.h>
28#include <linux/vmalloc.h>
29#include <linux/cpumask.h>
30#include <linux/atomic.h>
31#include <linux/kthread.h>
32#include <linux/crc32.h>
33#include <linux/ktime.h>
34
35#include "power.h"
36
37#define HIBERNATE_SIG "S1SUSPEND"
38
39/*
40 * When reading an {un,}compressed image, we may restore pages in place,
41 * in which case some architectures need these pages cleaning before they
42 * can be executed. We don't know which pages these may be, so clean the lot.
43 */
44static bool clean_pages_on_read;
45static bool clean_pages_on_decompress;
46
47/*
48 * The swap map is a data structure used for keeping track of each page
49 * written to a swap partition. It consists of many swap_map_page
50 * structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
51 * These structures are stored on the swap and linked together with the
52 * help of the .next_swap member.
53 *
54 * The swap map is created during suspend. The swap map pages are
55 * allocated and populated one at a time, so we only need one memory
56 * page to set up the entire structure.
57 *
58 * During resume we pick up all swap_map_page structures into a list.
59 */
60
61#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
62
63/*
64 * Number of free pages that are not high.
65 */
66static inline unsigned long low_free_pages(void)
67{
68 return nr_free_pages() - nr_free_highpages();
69}
70
71/*
72 * Number of pages required to be kept free while writing the image. Always
73 * half of all available low pages before the writing starts.
74 */
75static inline unsigned long reqd_free_pages(void)
76{
77 return low_free_pages() / 2;
78}
79
80struct swap_map_page {
81 sector_t entries[MAP_PAGE_ENTRIES];
82 sector_t next_swap;
83};
84
85struct swap_map_page_list {
86 struct swap_map_page *map;
87 struct swap_map_page_list *next;
88};
89
90/**
91 * The swap_map_handle structure is used for handling swap in
92 * a file-alike way
93 */
94
95struct swap_map_handle {
96 struct swap_map_page *cur;
97 struct swap_map_page_list *maps;
98 sector_t cur_swap;
99 sector_t first_sector;
100 unsigned int k;
101 unsigned long reqd_free_pages;
102 u32 crc32;
103};
104
105struct swsusp_header {
106 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
107 sizeof(u32)];
108 u32 crc32;
109 sector_t image;
110 unsigned int flags; /* Flags to pass to the "boot" kernel */
111 char orig_sig[10];
112 char sig[10];
113} __packed;
114
115static struct swsusp_header *swsusp_header;
116
117/**
118 * The following functions are used for tracing the allocated
119 * swap pages, so that they can be freed in case of an error.
120 */
121
122struct swsusp_extent {
123 struct rb_node node;
124 unsigned long start;
125 unsigned long end;
126};
127
128static struct rb_root swsusp_extents = RB_ROOT;
129
130static int swsusp_extents_insert(unsigned long swap_offset)
131{
132 struct rb_node **new = &(swsusp_extents.rb_node);
133 struct rb_node *parent = NULL;
134 struct swsusp_extent *ext;
135
136 /* Figure out where to put the new node */
137 while (*new) {
138 ext = rb_entry(*new, struct swsusp_extent, node);
139 parent = *new;
140 if (swap_offset < ext->start) {
141 /* Try to merge */
142 if (swap_offset == ext->start - 1) {
143 ext->start--;
144 return 0;
145 }
146 new = &((*new)->rb_left);
147 } else if (swap_offset > ext->end) {
148 /* Try to merge */
149 if (swap_offset == ext->end + 1) {
150 ext->end++;
151 return 0;
152 }
153 new = &((*new)->rb_right);
154 } else {
155 /* It already is in the tree */
156 return -EINVAL;
157 }
158 }
159 /* Add the new node and rebalance the tree. */
160 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
161 if (!ext)
162 return -ENOMEM;
163
164 ext->start = swap_offset;
165 ext->end = swap_offset;
166 rb_link_node(&ext->node, parent, new);
167 rb_insert_color(&ext->node, &swsusp_extents);
168 return 0;
169}
170
171/**
172 * alloc_swapdev_block - allocate a swap page and register that it has
173 * been allocated, so that it can be freed in case of an error.
174 */
175
176sector_t alloc_swapdev_block(int swap)
177{
178 unsigned long offset;
179
180 offset = swp_offset(get_swap_page_of_type(swap));
181 if (offset) {
182 if (swsusp_extents_insert(offset))
183 swap_free(swp_entry(swap, offset));
184 else
185 return swapdev_block(swap, offset);
186 }
187 return 0;
188}
189
190/**
191 * free_all_swap_pages - free swap pages allocated for saving image data.
192 * It also frees the extents used to register which swap entries had been
193 * allocated.
194 */
195
196void free_all_swap_pages(int swap)
197{
198 struct rb_node *node;
199
200 while ((node = swsusp_extents.rb_node)) {
201 struct swsusp_extent *ext;
202 unsigned long offset;
203
204 ext = rb_entry(node, struct swsusp_extent, node);
205 rb_erase(node, &swsusp_extents);
206 for (offset = ext->start; offset <= ext->end; offset++)
207 swap_free(swp_entry(swap, offset));
208
209 kfree(ext);
210 }
211}
212
213int swsusp_swap_in_use(void)
214{
215 return (swsusp_extents.rb_node != NULL);
216}
217
218/*
219 * General things
220 */
221
222static unsigned short root_swap = 0xffff;
223static struct block_device *hib_resume_bdev;
224
225struct hib_bio_batch {
226 atomic_t count;
227 wait_queue_head_t wait;
228 blk_status_t error;
229};
230
231static void hib_init_batch(struct hib_bio_batch *hb)
232{
233 atomic_set(&hb->count, 0);
234 init_waitqueue_head(&hb->wait);
235 hb->error = BLK_STS_OK;
236}
237
238static void hib_end_io(struct bio *bio)
239{
240 struct hib_bio_batch *hb = bio->bi_private;
241 struct page *page = bio_first_page_all(bio);
242
243 if (bio->bi_status) {
244 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
245 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
246 (unsigned long long)bio->bi_iter.bi_sector);
247 }
248
249 if (bio_data_dir(bio) == WRITE)
250 put_page(page);
251 else if (clean_pages_on_read)
252 flush_icache_range((unsigned long)page_address(page),
253 (unsigned long)page_address(page) + PAGE_SIZE);
254
255 if (bio->bi_status && !hb->error)
256 hb->error = bio->bi_status;
257 if (atomic_dec_and_test(&hb->count))
258 wake_up(&hb->wait);
259
260 bio_put(bio);
261}
262
263static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
264 struct hib_bio_batch *hb)
265{
266 struct page *page = virt_to_page(addr);
267 struct bio *bio;
268 int error = 0;
269
270 bio = bio_alloc(GFP_NOIO | __GFP_HIGH, 1);
271 bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
272 bio_set_dev(bio, hib_resume_bdev);
273 bio_set_op_attrs(bio, op, op_flags);
274
275 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
276 pr_err("Adding page to bio failed at %llu\n",
277 (unsigned long long)bio->bi_iter.bi_sector);
278 bio_put(bio);
279 return -EFAULT;
280 }
281
282 if (hb) {
283 bio->bi_end_io = hib_end_io;
284 bio->bi_private = hb;
285 atomic_inc(&hb->count);
286 submit_bio(bio);
287 } else {
288 error = submit_bio_wait(bio);
289 bio_put(bio);
290 }
291
292 return error;
293}
294
295static blk_status_t hib_wait_io(struct hib_bio_batch *hb)
296{
297 wait_event(hb->wait, atomic_read(&hb->count) == 0);
298 return blk_status_to_errno(hb->error);
299}
300
301/*
302 * Saving part
303 */
304
305static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
306{
307 int error;
308
309 hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
310 swsusp_header, NULL);
311 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
312 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
313 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
314 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
315 swsusp_header->image = handle->first_sector;
316 swsusp_header->flags = flags;
317 if (flags & SF_CRC32_MODE)
318 swsusp_header->crc32 = handle->crc32;
319 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
320 swsusp_resume_block, swsusp_header, NULL);
321 } else {
322 pr_err("Swap header not found!\n");
323 error = -ENODEV;
324 }
325 return error;
326}
327
328/**
329 * swsusp_swap_check - check if the resume device is a swap device
330 * and get its index (if so)
331 *
332 * This is called before saving image
333 */
334static int swsusp_swap_check(void)
335{
336 int res;
337
338 res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
339 &hib_resume_bdev);
340 if (res < 0)
341 return res;
342
343 root_swap = res;
344 res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
345 if (res)
346 return res;
347
348 res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
349 if (res < 0)
350 blkdev_put(hib_resume_bdev, FMODE_WRITE);
351
352 /*
353 * Update the resume device to the one actually used,
354 * so the test_resume mode can use it in case it is
355 * invoked from hibernate() to test the snapshot.
356 */
357 swsusp_resume_device = hib_resume_bdev->bd_dev;
358 return res;
359}
360
361/**
362 * write_page - Write one page to given swap location.
363 * @buf: Address we're writing.
364 * @offset: Offset of the swap page we're writing to.
365 * @hb: bio completion batch
366 */
367
368static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
369{
370 void *src;
371 int ret;
372
373 if (!offset)
374 return -ENOSPC;
375
376 if (hb) {
377 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
378 __GFP_NORETRY);
379 if (src) {
380 copy_page(src, buf);
381 } else {
382 ret = hib_wait_io(hb); /* Free pages */
383 if (ret)
384 return ret;
385 src = (void *)__get_free_page(GFP_NOIO |
386 __GFP_NOWARN |
387 __GFP_NORETRY);
388 if (src) {
389 copy_page(src, buf);
390 } else {
391 WARN_ON_ONCE(1);
392 hb = NULL; /* Go synchronous */
393 src = buf;
394 }
395 }
396 } else {
397 src = buf;
398 }
399 return hib_submit_io(REQ_OP_WRITE, REQ_SYNC, offset, src, hb);
400}
401
402static void release_swap_writer(struct swap_map_handle *handle)
403{
404 if (handle->cur)
405 free_page((unsigned long)handle->cur);
406 handle->cur = NULL;
407}
408
409static int get_swap_writer(struct swap_map_handle *handle)
410{
411 int ret;
412
413 ret = swsusp_swap_check();
414 if (ret) {
415 if (ret != -ENOSPC)
416 pr_err("Cannot find swap device, try swapon -a\n");
417 return ret;
418 }
419 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
420 if (!handle->cur) {
421 ret = -ENOMEM;
422 goto err_close;
423 }
424 handle->cur_swap = alloc_swapdev_block(root_swap);
425 if (!handle->cur_swap) {
426 ret = -ENOSPC;
427 goto err_rel;
428 }
429 handle->k = 0;
430 handle->reqd_free_pages = reqd_free_pages();
431 handle->first_sector = handle->cur_swap;
432 return 0;
433err_rel:
434 release_swap_writer(handle);
435err_close:
436 swsusp_close(FMODE_WRITE);
437 return ret;
438}
439
440static int swap_write_page(struct swap_map_handle *handle, void *buf,
441 struct hib_bio_batch *hb)
442{
443 int error = 0;
444 sector_t offset;
445
446 if (!handle->cur)
447 return -EINVAL;
448 offset = alloc_swapdev_block(root_swap);
449 error = write_page(buf, offset, hb);
450 if (error)
451 return error;
452 handle->cur->entries[handle->k++] = offset;
453 if (handle->k >= MAP_PAGE_ENTRIES) {
454 offset = alloc_swapdev_block(root_swap);
455 if (!offset)
456 return -ENOSPC;
457 handle->cur->next_swap = offset;
458 error = write_page(handle->cur, handle->cur_swap, hb);
459 if (error)
460 goto out;
461 clear_page(handle->cur);
462 handle->cur_swap = offset;
463 handle->k = 0;
464
465 if (hb && low_free_pages() <= handle->reqd_free_pages) {
466 error = hib_wait_io(hb);
467 if (error)
468 goto out;
469 /*
470 * Recalculate the number of required free pages, to
471 * make sure we never take more than half.
472 */
473 handle->reqd_free_pages = reqd_free_pages();
474 }
475 }
476 out:
477 return error;
478}
479
480static int flush_swap_writer(struct swap_map_handle *handle)
481{
482 if (handle->cur && handle->cur_swap)
483 return write_page(handle->cur, handle->cur_swap, NULL);
484 else
485 return -EINVAL;
486}
487
488static int swap_writer_finish(struct swap_map_handle *handle,
489 unsigned int flags, int error)
490{
491 if (!error) {
492 flush_swap_writer(handle);
493 pr_info("S");
494 error = mark_swapfiles(handle, flags);
495 pr_cont("|\n");
496 }
497
498 if (error)
499 free_all_swap_pages(root_swap);
500 release_swap_writer(handle);
501 swsusp_close(FMODE_WRITE);
502
503 return error;
504}
505
506/* We need to remember how much compressed data we need to read. */
507#define LZO_HEADER sizeof(size_t)
508
509/* Number of pages/bytes we'll compress at one time. */
510#define LZO_UNC_PAGES 32
511#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE)
512
513/* Number of pages/bytes we need for compressed data (worst case). */
514#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
515 LZO_HEADER, PAGE_SIZE)
516#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE)
517
518/* Maximum number of threads for compression/decompression. */
519#define LZO_THREADS 3
520
521/* Minimum/maximum number of pages for read buffering. */
522#define LZO_MIN_RD_PAGES 1024
523#define LZO_MAX_RD_PAGES 8192
524
525
526/**
527 * save_image - save the suspend image data
528 */
529
530static int save_image(struct swap_map_handle *handle,
531 struct snapshot_handle *snapshot,
532 unsigned int nr_to_write)
533{
534 unsigned int m;
535 int ret;
536 int nr_pages;
537 int err2;
538 struct hib_bio_batch hb;
539 ktime_t start;
540 ktime_t stop;
541
542 hib_init_batch(&hb);
543
544 pr_info("Saving image data pages (%u pages)...\n",
545 nr_to_write);
546 m = nr_to_write / 10;
547 if (!m)
548 m = 1;
549 nr_pages = 0;
550 start = ktime_get();
551 while (1) {
552 ret = snapshot_read_next(snapshot);
553 if (ret <= 0)
554 break;
555 ret = swap_write_page(handle, data_of(*snapshot), &hb);
556 if (ret)
557 break;
558 if (!(nr_pages % m))
559 pr_info("Image saving progress: %3d%%\n",
560 nr_pages / m * 10);
561 nr_pages++;
562 }
563 err2 = hib_wait_io(&hb);
564 stop = ktime_get();
565 if (!ret)
566 ret = err2;
567 if (!ret)
568 pr_info("Image saving done\n");
569 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
570 return ret;
571}
572
573/**
574 * Structure used for CRC32.
575 */
576struct crc_data {
577 struct task_struct *thr; /* thread */
578 atomic_t ready; /* ready to start flag */
579 atomic_t stop; /* ready to stop flag */
580 unsigned run_threads; /* nr current threads */
581 wait_queue_head_t go; /* start crc update */
582 wait_queue_head_t done; /* crc update done */
583 u32 *crc32; /* points to handle's crc32 */
584 size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */
585 unsigned char *unc[LZO_THREADS]; /* uncompressed data */
586};
587
588/**
589 * CRC32 update function that runs in its own thread.
590 */
591static int crc32_threadfn(void *data)
592{
593 struct crc_data *d = data;
594 unsigned i;
595
596 while (1) {
597 wait_event(d->go, atomic_read(&d->ready) ||
598 kthread_should_stop());
599 if (kthread_should_stop()) {
600 d->thr = NULL;
601 atomic_set(&d->stop, 1);
602 wake_up(&d->done);
603 break;
604 }
605 atomic_set(&d->ready, 0);
606
607 for (i = 0; i < d->run_threads; i++)
608 *d->crc32 = crc32_le(*d->crc32,
609 d->unc[i], *d->unc_len[i]);
610 atomic_set(&d->stop, 1);
611 wake_up(&d->done);
612 }
613 return 0;
614}
615/**
616 * Structure used for LZO data compression.
617 */
618struct cmp_data {
619 struct task_struct *thr; /* thread */
620 atomic_t ready; /* ready to start flag */
621 atomic_t stop; /* ready to stop flag */
622 int ret; /* return code */
623 wait_queue_head_t go; /* start compression */
624 wait_queue_head_t done; /* compression done */
625 size_t unc_len; /* uncompressed length */
626 size_t cmp_len; /* compressed length */
627 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
628 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
629 unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
630};
631
632/**
633 * Compression function that runs in its own thread.
634 */
635static int lzo_compress_threadfn(void *data)
636{
637 struct cmp_data *d = data;
638
639 while (1) {
640 wait_event(d->go, atomic_read(&d->ready) ||
641 kthread_should_stop());
642 if (kthread_should_stop()) {
643 d->thr = NULL;
644 d->ret = -1;
645 atomic_set(&d->stop, 1);
646 wake_up(&d->done);
647 break;
648 }
649 atomic_set(&d->ready, 0);
650
651 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
652 d->cmp + LZO_HEADER, &d->cmp_len,
653 d->wrk);
654 atomic_set(&d->stop, 1);
655 wake_up(&d->done);
656 }
657 return 0;
658}
659
660/**
661 * save_image_lzo - Save the suspend image data compressed with LZO.
662 * @handle: Swap map handle to use for saving the image.
663 * @snapshot: Image to read data from.
664 * @nr_to_write: Number of pages to save.
665 */
666static int save_image_lzo(struct swap_map_handle *handle,
667 struct snapshot_handle *snapshot,
668 unsigned int nr_to_write)
669{
670 unsigned int m;
671 int ret = 0;
672 int nr_pages;
673 int err2;
674 struct hib_bio_batch hb;
675 ktime_t start;
676 ktime_t stop;
677 size_t off;
678 unsigned thr, run_threads, nr_threads;
679 unsigned char *page = NULL;
680 struct cmp_data *data = NULL;
681 struct crc_data *crc = NULL;
682
683 hib_init_batch(&hb);
684
685 /*
686 * We'll limit the number of threads for compression to limit memory
687 * footprint.
688 */
689 nr_threads = num_online_cpus() - 1;
690 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
691
692 page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
693 if (!page) {
694 pr_err("Failed to allocate LZO page\n");
695 ret = -ENOMEM;
696 goto out_clean;
697 }
698
699 data = vmalloc(array_size(nr_threads, sizeof(*data)));
700 if (!data) {
701 pr_err("Failed to allocate LZO data\n");
702 ret = -ENOMEM;
703 goto out_clean;
704 }
705 for (thr = 0; thr < nr_threads; thr++)
706 memset(&data[thr], 0, offsetof(struct cmp_data, go));
707
708 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
709 if (!crc) {
710 pr_err("Failed to allocate crc\n");
711 ret = -ENOMEM;
712 goto out_clean;
713 }
714 memset(crc, 0, offsetof(struct crc_data, go));
715
716 /*
717 * Start the compression threads.
718 */
719 for (thr = 0; thr < nr_threads; thr++) {
720 init_waitqueue_head(&data[thr].go);
721 init_waitqueue_head(&data[thr].done);
722
723 data[thr].thr = kthread_run(lzo_compress_threadfn,
724 &data[thr],
725 "image_compress/%u", thr);
726 if (IS_ERR(data[thr].thr)) {
727 data[thr].thr = NULL;
728 pr_err("Cannot start compression threads\n");
729 ret = -ENOMEM;
730 goto out_clean;
731 }
732 }
733
734 /*
735 * Start the CRC32 thread.
736 */
737 init_waitqueue_head(&crc->go);
738 init_waitqueue_head(&crc->done);
739
740 handle->crc32 = 0;
741 crc->crc32 = &handle->crc32;
742 for (thr = 0; thr < nr_threads; thr++) {
743 crc->unc[thr] = data[thr].unc;
744 crc->unc_len[thr] = &data[thr].unc_len;
745 }
746
747 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
748 if (IS_ERR(crc->thr)) {
749 crc->thr = NULL;
750 pr_err("Cannot start CRC32 thread\n");
751 ret = -ENOMEM;
752 goto out_clean;
753 }
754
755 /*
756 * Adjust the number of required free pages after all allocations have
757 * been done. We don't want to run out of pages when writing.
758 */
759 handle->reqd_free_pages = reqd_free_pages();
760
761 pr_info("Using %u thread(s) for compression\n", nr_threads);
762 pr_info("Compressing and saving image data (%u pages)...\n",
763 nr_to_write);
764 m = nr_to_write / 10;
765 if (!m)
766 m = 1;
767 nr_pages = 0;
768 start = ktime_get();
769 for (;;) {
770 for (thr = 0; thr < nr_threads; thr++) {
771 for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
772 ret = snapshot_read_next(snapshot);
773 if (ret < 0)
774 goto out_finish;
775
776 if (!ret)
777 break;
778
779 memcpy(data[thr].unc + off,
780 data_of(*snapshot), PAGE_SIZE);
781
782 if (!(nr_pages % m))
783 pr_info("Image saving progress: %3d%%\n",
784 nr_pages / m * 10);
785 nr_pages++;
786 }
787 if (!off)
788 break;
789
790 data[thr].unc_len = off;
791
792 atomic_set(&data[thr].ready, 1);
793 wake_up(&data[thr].go);
794 }
795
796 if (!thr)
797 break;
798
799 crc->run_threads = thr;
800 atomic_set(&crc->ready, 1);
801 wake_up(&crc->go);
802
803 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
804 wait_event(data[thr].done,
805 atomic_read(&data[thr].stop));
806 atomic_set(&data[thr].stop, 0);
807
808 ret = data[thr].ret;
809
810 if (ret < 0) {
811 pr_err("LZO compression failed\n");
812 goto out_finish;
813 }
814
815 if (unlikely(!data[thr].cmp_len ||
816 data[thr].cmp_len >
817 lzo1x_worst_compress(data[thr].unc_len))) {
818 pr_err("Invalid LZO compressed length\n");
819 ret = -1;
820 goto out_finish;
821 }
822
823 *(size_t *)data[thr].cmp = data[thr].cmp_len;
824
825 /*
826 * Given we are writing one page at a time to disk, we
827 * copy that much from the buffer, although the last
828 * bit will likely be smaller than full page. This is
829 * OK - we saved the length of the compressed data, so
830 * any garbage at the end will be discarded when we
831 * read it.
832 */
833 for (off = 0;
834 off < LZO_HEADER + data[thr].cmp_len;
835 off += PAGE_SIZE) {
836 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
837
838 ret = swap_write_page(handle, page, &hb);
839 if (ret)
840 goto out_finish;
841 }
842 }
843
844 wait_event(crc->done, atomic_read(&crc->stop));
845 atomic_set(&crc->stop, 0);
846 }
847
848out_finish:
849 err2 = hib_wait_io(&hb);
850 stop = ktime_get();
851 if (!ret)
852 ret = err2;
853 if (!ret)
854 pr_info("Image saving done\n");
855 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
856out_clean:
857 if (crc) {
858 if (crc->thr)
859 kthread_stop(crc->thr);
860 kfree(crc);
861 }
862 if (data) {
863 for (thr = 0; thr < nr_threads; thr++)
864 if (data[thr].thr)
865 kthread_stop(data[thr].thr);
866 vfree(data);
867 }
868 if (page) free_page((unsigned long)page);
869
870 return ret;
871}
872
873/**
874 * enough_swap - Make sure we have enough swap to save the image.
875 *
876 * Returns TRUE or FALSE after checking the total amount of swap
877 * space avaiable from the resume partition.
878 */
879
880static int enough_swap(unsigned int nr_pages)
881{
882 unsigned int free_swap = count_swap_pages(root_swap, 1);
883 unsigned int required;
884
885 pr_debug("Free swap pages: %u\n", free_swap);
886
887 required = PAGES_FOR_IO + nr_pages;
888 return free_swap > required;
889}
890
891/**
892 * swsusp_write - Write entire image and metadata.
893 * @flags: flags to pass to the "boot" kernel in the image header
894 *
895 * It is important _NOT_ to umount filesystems at this point. We want
896 * them synced (in case something goes wrong) but we DO not want to mark
897 * filesystem clean: it is not. (And it does not matter, if we resume
898 * correctly, we'll mark system clean, anyway.)
899 */
900
901int swsusp_write(unsigned int flags)
902{
903 struct swap_map_handle handle;
904 struct snapshot_handle snapshot;
905 struct swsusp_info *header;
906 unsigned long pages;
907 int error;
908
909 pages = snapshot_get_image_size();
910 error = get_swap_writer(&handle);
911 if (error) {
912 pr_err("Cannot get swap writer\n");
913 return error;
914 }
915 if (flags & SF_NOCOMPRESS_MODE) {
916 if (!enough_swap(pages)) {
917 pr_err("Not enough free swap\n");
918 error = -ENOSPC;
919 goto out_finish;
920 }
921 }
922 memset(&snapshot, 0, sizeof(struct snapshot_handle));
923 error = snapshot_read_next(&snapshot);
924 if (error < (int)PAGE_SIZE) {
925 if (error >= 0)
926 error = -EFAULT;
927
928 goto out_finish;
929 }
930 header = (struct swsusp_info *)data_of(snapshot);
931 error = swap_write_page(&handle, header, NULL);
932 if (!error) {
933 error = (flags & SF_NOCOMPRESS_MODE) ?
934 save_image(&handle, &snapshot, pages - 1) :
935 save_image_lzo(&handle, &snapshot, pages - 1);
936 }
937out_finish:
938 error = swap_writer_finish(&handle, flags, error);
939 return error;
940}
941
942/**
943 * The following functions allow us to read data using a swap map
944 * in a file-alike way
945 */
946
947static void release_swap_reader(struct swap_map_handle *handle)
948{
949 struct swap_map_page_list *tmp;
950
951 while (handle->maps) {
952 if (handle->maps->map)
953 free_page((unsigned long)handle->maps->map);
954 tmp = handle->maps;
955 handle->maps = handle->maps->next;
956 kfree(tmp);
957 }
958 handle->cur = NULL;
959}
960
961static int get_swap_reader(struct swap_map_handle *handle,
962 unsigned int *flags_p)
963{
964 int error;
965 struct swap_map_page_list *tmp, *last;
966 sector_t offset;
967
968 *flags_p = swsusp_header->flags;
969
970 if (!swsusp_header->image) /* how can this happen? */
971 return -EINVAL;
972
973 handle->cur = NULL;
974 last = handle->maps = NULL;
975 offset = swsusp_header->image;
976 while (offset) {
977 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
978 if (!tmp) {
979 release_swap_reader(handle);
980 return -ENOMEM;
981 }
982 if (!handle->maps)
983 handle->maps = tmp;
984 if (last)
985 last->next = tmp;
986 last = tmp;
987
988 tmp->map = (struct swap_map_page *)
989 __get_free_page(GFP_NOIO | __GFP_HIGH);
990 if (!tmp->map) {
991 release_swap_reader(handle);
992 return -ENOMEM;
993 }
994
995 error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL);
996 if (error) {
997 release_swap_reader(handle);
998 return error;
999 }
1000 offset = tmp->map->next_swap;
1001 }
1002 handle->k = 0;
1003 handle->cur = handle->maps->map;
1004 return 0;
1005}
1006
1007static int swap_read_page(struct swap_map_handle *handle, void *buf,
1008 struct hib_bio_batch *hb)
1009{
1010 sector_t offset;
1011 int error;
1012 struct swap_map_page_list *tmp;
1013
1014 if (!handle->cur)
1015 return -EINVAL;
1016 offset = handle->cur->entries[handle->k];
1017 if (!offset)
1018 return -EFAULT;
1019 error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb);
1020 if (error)
1021 return error;
1022 if (++handle->k >= MAP_PAGE_ENTRIES) {
1023 handle->k = 0;
1024 free_page((unsigned long)handle->maps->map);
1025 tmp = handle->maps;
1026 handle->maps = handle->maps->next;
1027 kfree(tmp);
1028 if (!handle->maps)
1029 release_swap_reader(handle);
1030 else
1031 handle->cur = handle->maps->map;
1032 }
1033 return error;
1034}
1035
1036static int swap_reader_finish(struct swap_map_handle *handle)
1037{
1038 release_swap_reader(handle);
1039
1040 return 0;
1041}
1042
1043/**
1044 * load_image - load the image using the swap map handle
1045 * @handle and the snapshot handle @snapshot
1046 * (assume there are @nr_pages pages to load)
1047 */
1048
1049static int load_image(struct swap_map_handle *handle,
1050 struct snapshot_handle *snapshot,
1051 unsigned int nr_to_read)
1052{
1053 unsigned int m;
1054 int ret = 0;
1055 ktime_t start;
1056 ktime_t stop;
1057 struct hib_bio_batch hb;
1058 int err2;
1059 unsigned nr_pages;
1060
1061 hib_init_batch(&hb);
1062
1063 clean_pages_on_read = true;
1064 pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1065 m = nr_to_read / 10;
1066 if (!m)
1067 m = 1;
1068 nr_pages = 0;
1069 start = ktime_get();
1070 for ( ; ; ) {
1071 ret = snapshot_write_next(snapshot);
1072 if (ret <= 0)
1073 break;
1074 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1075 if (ret)
1076 break;
1077 if (snapshot->sync_read)
1078 ret = hib_wait_io(&hb);
1079 if (ret)
1080 break;
1081 if (!(nr_pages % m))
1082 pr_info("Image loading progress: %3d%%\n",
1083 nr_pages / m * 10);
1084 nr_pages++;
1085 }
1086 err2 = hib_wait_io(&hb);
1087 stop = ktime_get();
1088 if (!ret)
1089 ret = err2;
1090 if (!ret) {
1091 pr_info("Image loading done\n");
1092 snapshot_write_finalize(snapshot);
1093 if (!snapshot_image_loaded(snapshot))
1094 ret = -ENODATA;
1095 }
1096 swsusp_show_speed(start, stop, nr_to_read, "Read");
1097 return ret;
1098}
1099
1100/**
1101 * Structure used for LZO data decompression.
1102 */
1103struct dec_data {
1104 struct task_struct *thr; /* thread */
1105 atomic_t ready; /* ready to start flag */
1106 atomic_t stop; /* ready to stop flag */
1107 int ret; /* return code */
1108 wait_queue_head_t go; /* start decompression */
1109 wait_queue_head_t done; /* decompression done */
1110 size_t unc_len; /* uncompressed length */
1111 size_t cmp_len; /* compressed length */
1112 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
1113 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
1114};
1115
1116/**
1117 * Deompression function that runs in its own thread.
1118 */
1119static int lzo_decompress_threadfn(void *data)
1120{
1121 struct dec_data *d = data;
1122
1123 while (1) {
1124 wait_event(d->go, atomic_read(&d->ready) ||
1125 kthread_should_stop());
1126 if (kthread_should_stop()) {
1127 d->thr = NULL;
1128 d->ret = -1;
1129 atomic_set(&d->stop, 1);
1130 wake_up(&d->done);
1131 break;
1132 }
1133 atomic_set(&d->ready, 0);
1134
1135 d->unc_len = LZO_UNC_SIZE;
1136 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1137 d->unc, &d->unc_len);
1138 if (clean_pages_on_decompress)
1139 flush_icache_range((unsigned long)d->unc,
1140 (unsigned long)d->unc + d->unc_len);
1141
1142 atomic_set(&d->stop, 1);
1143 wake_up(&d->done);
1144 }
1145 return 0;
1146}
1147
1148/**
1149 * load_image_lzo - Load compressed image data and decompress them with LZO.
1150 * @handle: Swap map handle to use for loading data.
1151 * @snapshot: Image to copy uncompressed data into.
1152 * @nr_to_read: Number of pages to load.
1153 */
1154static int load_image_lzo(struct swap_map_handle *handle,
1155 struct snapshot_handle *snapshot,
1156 unsigned int nr_to_read)
1157{
1158 unsigned int m;
1159 int ret = 0;
1160 int eof = 0;
1161 struct hib_bio_batch hb;
1162 ktime_t start;
1163 ktime_t stop;
1164 unsigned nr_pages;
1165 size_t off;
1166 unsigned i, thr, run_threads, nr_threads;
1167 unsigned ring = 0, pg = 0, ring_size = 0,
1168 have = 0, want, need, asked = 0;
1169 unsigned long read_pages = 0;
1170 unsigned char **page = NULL;
1171 struct dec_data *data = NULL;
1172 struct crc_data *crc = NULL;
1173
1174 hib_init_batch(&hb);
1175
1176 /*
1177 * We'll limit the number of threads for decompression to limit memory
1178 * footprint.
1179 */
1180 nr_threads = num_online_cpus() - 1;
1181 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1182
1183 page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
1184 if (!page) {
1185 pr_err("Failed to allocate LZO page\n");
1186 ret = -ENOMEM;
1187 goto out_clean;
1188 }
1189
1190 data = vmalloc(array_size(nr_threads, sizeof(*data)));
1191 if (!data) {
1192 pr_err("Failed to allocate LZO data\n");
1193 ret = -ENOMEM;
1194 goto out_clean;
1195 }
1196 for (thr = 0; thr < nr_threads; thr++)
1197 memset(&data[thr], 0, offsetof(struct dec_data, go));
1198
1199 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1200 if (!crc) {
1201 pr_err("Failed to allocate crc\n");
1202 ret = -ENOMEM;
1203 goto out_clean;
1204 }
1205 memset(crc, 0, offsetof(struct crc_data, go));
1206
1207 clean_pages_on_decompress = true;
1208
1209 /*
1210 * Start the decompression threads.
1211 */
1212 for (thr = 0; thr < nr_threads; thr++) {
1213 init_waitqueue_head(&data[thr].go);
1214 init_waitqueue_head(&data[thr].done);
1215
1216 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1217 &data[thr],
1218 "image_decompress/%u", thr);
1219 if (IS_ERR(data[thr].thr)) {
1220 data[thr].thr = NULL;
1221 pr_err("Cannot start decompression threads\n");
1222 ret = -ENOMEM;
1223 goto out_clean;
1224 }
1225 }
1226
1227 /*
1228 * Start the CRC32 thread.
1229 */
1230 init_waitqueue_head(&crc->go);
1231 init_waitqueue_head(&crc->done);
1232
1233 handle->crc32 = 0;
1234 crc->crc32 = &handle->crc32;
1235 for (thr = 0; thr < nr_threads; thr++) {
1236 crc->unc[thr] = data[thr].unc;
1237 crc->unc_len[thr] = &data[thr].unc_len;
1238 }
1239
1240 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1241 if (IS_ERR(crc->thr)) {
1242 crc->thr = NULL;
1243 pr_err("Cannot start CRC32 thread\n");
1244 ret = -ENOMEM;
1245 goto out_clean;
1246 }
1247
1248 /*
1249 * Set the number of pages for read buffering.
1250 * This is complete guesswork, because we'll only know the real
1251 * picture once prepare_image() is called, which is much later on
1252 * during the image load phase. We'll assume the worst case and
1253 * say that none of the image pages are from high memory.
1254 */
1255 if (low_free_pages() > snapshot_get_image_size())
1256 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1257 read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1258
1259 for (i = 0; i < read_pages; i++) {
1260 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1261 GFP_NOIO | __GFP_HIGH :
1262 GFP_NOIO | __GFP_NOWARN |
1263 __GFP_NORETRY);
1264
1265 if (!page[i]) {
1266 if (i < LZO_CMP_PAGES) {
1267 ring_size = i;
1268 pr_err("Failed to allocate LZO pages\n");
1269 ret = -ENOMEM;
1270 goto out_clean;
1271 } else {
1272 break;
1273 }
1274 }
1275 }
1276 want = ring_size = i;
1277
1278 pr_info("Using %u thread(s) for decompression\n", nr_threads);
1279 pr_info("Loading and decompressing image data (%u pages)...\n",
1280 nr_to_read);
1281 m = nr_to_read / 10;
1282 if (!m)
1283 m = 1;
1284 nr_pages = 0;
1285 start = ktime_get();
1286
1287 ret = snapshot_write_next(snapshot);
1288 if (ret <= 0)
1289 goto out_finish;
1290
1291 for(;;) {
1292 for (i = 0; !eof && i < want; i++) {
1293 ret = swap_read_page(handle, page[ring], &hb);
1294 if (ret) {
1295 /*
1296 * On real read error, finish. On end of data,
1297 * set EOF flag and just exit the read loop.
1298 */
1299 if (handle->cur &&
1300 handle->cur->entries[handle->k]) {
1301 goto out_finish;
1302 } else {
1303 eof = 1;
1304 break;
1305 }
1306 }
1307 if (++ring >= ring_size)
1308 ring = 0;
1309 }
1310 asked += i;
1311 want -= i;
1312
1313 /*
1314 * We are out of data, wait for some more.
1315 */
1316 if (!have) {
1317 if (!asked)
1318 break;
1319
1320 ret = hib_wait_io(&hb);
1321 if (ret)
1322 goto out_finish;
1323 have += asked;
1324 asked = 0;
1325 if (eof)
1326 eof = 2;
1327 }
1328
1329 if (crc->run_threads) {
1330 wait_event(crc->done, atomic_read(&crc->stop));
1331 atomic_set(&crc->stop, 0);
1332 crc->run_threads = 0;
1333 }
1334
1335 for (thr = 0; have && thr < nr_threads; thr++) {
1336 data[thr].cmp_len = *(size_t *)page[pg];
1337 if (unlikely(!data[thr].cmp_len ||
1338 data[thr].cmp_len >
1339 lzo1x_worst_compress(LZO_UNC_SIZE))) {
1340 pr_err("Invalid LZO compressed length\n");
1341 ret = -1;
1342 goto out_finish;
1343 }
1344
1345 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1346 PAGE_SIZE);
1347 if (need > have) {
1348 if (eof > 1) {
1349 ret = -1;
1350 goto out_finish;
1351 }
1352 break;
1353 }
1354
1355 for (off = 0;
1356 off < LZO_HEADER + data[thr].cmp_len;
1357 off += PAGE_SIZE) {
1358 memcpy(data[thr].cmp + off,
1359 page[pg], PAGE_SIZE);
1360 have--;
1361 want++;
1362 if (++pg >= ring_size)
1363 pg = 0;
1364 }
1365
1366 atomic_set(&data[thr].ready, 1);
1367 wake_up(&data[thr].go);
1368 }
1369
1370 /*
1371 * Wait for more data while we are decompressing.
1372 */
1373 if (have < LZO_CMP_PAGES && asked) {
1374 ret = hib_wait_io(&hb);
1375 if (ret)
1376 goto out_finish;
1377 have += asked;
1378 asked = 0;
1379 if (eof)
1380 eof = 2;
1381 }
1382
1383 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1384 wait_event(data[thr].done,
1385 atomic_read(&data[thr].stop));
1386 atomic_set(&data[thr].stop, 0);
1387
1388 ret = data[thr].ret;
1389
1390 if (ret < 0) {
1391 pr_err("LZO decompression failed\n");
1392 goto out_finish;
1393 }
1394
1395 if (unlikely(!data[thr].unc_len ||
1396 data[thr].unc_len > LZO_UNC_SIZE ||
1397 data[thr].unc_len & (PAGE_SIZE - 1))) {
1398 pr_err("Invalid LZO uncompressed length\n");
1399 ret = -1;
1400 goto out_finish;
1401 }
1402
1403 for (off = 0;
1404 off < data[thr].unc_len; off += PAGE_SIZE) {
1405 memcpy(data_of(*snapshot),
1406 data[thr].unc + off, PAGE_SIZE);
1407
1408 if (!(nr_pages % m))
1409 pr_info("Image loading progress: %3d%%\n",
1410 nr_pages / m * 10);
1411 nr_pages++;
1412
1413 ret = snapshot_write_next(snapshot);
1414 if (ret <= 0) {
1415 crc->run_threads = thr + 1;
1416 atomic_set(&crc->ready, 1);
1417 wake_up(&crc->go);
1418 goto out_finish;
1419 }
1420 }
1421 }
1422
1423 crc->run_threads = thr;
1424 atomic_set(&crc->ready, 1);
1425 wake_up(&crc->go);
1426 }
1427
1428out_finish:
1429 if (crc->run_threads) {
1430 wait_event(crc->done, atomic_read(&crc->stop));
1431 atomic_set(&crc->stop, 0);
1432 }
1433 stop = ktime_get();
1434 if (!ret) {
1435 pr_info("Image loading done\n");
1436 snapshot_write_finalize(snapshot);
1437 if (!snapshot_image_loaded(snapshot))
1438 ret = -ENODATA;
1439 if (!ret) {
1440 if (swsusp_header->flags & SF_CRC32_MODE) {
1441 if(handle->crc32 != swsusp_header->crc32) {
1442 pr_err("Invalid image CRC32!\n");
1443 ret = -ENODATA;
1444 }
1445 }
1446 }
1447 }
1448 swsusp_show_speed(start, stop, nr_to_read, "Read");
1449out_clean:
1450 for (i = 0; i < ring_size; i++)
1451 free_page((unsigned long)page[i]);
1452 if (crc) {
1453 if (crc->thr)
1454 kthread_stop(crc->thr);
1455 kfree(crc);
1456 }
1457 if (data) {
1458 for (thr = 0; thr < nr_threads; thr++)
1459 if (data[thr].thr)
1460 kthread_stop(data[thr].thr);
1461 vfree(data);
1462 }
1463 vfree(page);
1464
1465 return ret;
1466}
1467
1468/**
1469 * swsusp_read - read the hibernation image.
1470 * @flags_p: flags passed by the "frozen" kernel in the image header should
1471 * be written into this memory location
1472 */
1473
1474int swsusp_read(unsigned int *flags_p)
1475{
1476 int error;
1477 struct swap_map_handle handle;
1478 struct snapshot_handle snapshot;
1479 struct swsusp_info *header;
1480
1481 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1482 error = snapshot_write_next(&snapshot);
1483 if (error < (int)PAGE_SIZE)
1484 return error < 0 ? error : -EFAULT;
1485 header = (struct swsusp_info *)data_of(snapshot);
1486 error = get_swap_reader(&handle, flags_p);
1487 if (error)
1488 goto end;
1489 if (!error)
1490 error = swap_read_page(&handle, header, NULL);
1491 if (!error) {
1492 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1493 load_image(&handle, &snapshot, header->pages - 1) :
1494 load_image_lzo(&handle, &snapshot, header->pages - 1);
1495 }
1496 swap_reader_finish(&handle);
1497end:
1498 if (!error)
1499 pr_debug("Image successfully loaded\n");
1500 else
1501 pr_debug("Error %d resuming\n", error);
1502 return error;
1503}
1504
1505/**
1506 * swsusp_check - Check for swsusp signature in the resume device
1507 */
1508
1509int swsusp_check(void)
1510{
1511 int error;
1512
1513 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1514 FMODE_READ, NULL);
1515 if (!IS_ERR(hib_resume_bdev)) {
1516 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1517 clear_page(swsusp_header);
1518 error = hib_submit_io(REQ_OP_READ, 0,
1519 swsusp_resume_block,
1520 swsusp_header, NULL);
1521 if (error)
1522 goto put;
1523
1524 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1525 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1526 /* Reset swap signature now */
1527 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1528 swsusp_resume_block,
1529 swsusp_header, NULL);
1530 } else {
1531 error = -EINVAL;
1532 }
1533
1534put:
1535 if (error)
1536 blkdev_put(hib_resume_bdev, FMODE_READ);
1537 else
1538 pr_debug("Image signature found, resuming\n");
1539 } else {
1540 error = PTR_ERR(hib_resume_bdev);
1541 }
1542
1543 if (error)
1544 pr_debug("Image not found (code %d)\n", error);
1545
1546 return error;
1547}
1548
1549/**
1550 * swsusp_close - close swap device.
1551 */
1552
1553void swsusp_close(fmode_t mode)
1554{
1555 if (IS_ERR(hib_resume_bdev)) {
1556 pr_debug("Image device not initialised\n");
1557 return;
1558 }
1559
1560 blkdev_put(hib_resume_bdev, mode);
1561}
1562
1563/**
1564 * swsusp_unmark - Unmark swsusp signature in the resume device
1565 */
1566
1567#ifdef CONFIG_SUSPEND
1568int swsusp_unmark(void)
1569{
1570 int error;
1571
1572 hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
1573 swsusp_header, NULL);
1574 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1575 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1576 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1577 swsusp_resume_block,
1578 swsusp_header, NULL);
1579 } else {
1580 pr_err("Cannot find swsusp signature!\n");
1581 error = -ENODEV;
1582 }
1583
1584 /*
1585 * We just returned from suspend, we don't need the image any more.
1586 */
1587 free_all_swap_pages(root_swap);
1588
1589 return error;
1590}
1591#endif
1592
1593static int __init swsusp_header_init(void)
1594{
1595 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1596 if (!swsusp_header)
1597 panic("Could not allocate memory for swsusp_header\n");
1598 return 0;
1599}
1600
1601core_initcall(swsusp_header_init);
1/*
2 * linux/kernel/power/swap.c
3 *
4 * This file provides functions for reading the suspend image from
5 * and writing it to a swap partition.
6 *
7 * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
8 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
10 *
11 * This file is released under the GPLv2.
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/file.h>
17#include <linux/delay.h>
18#include <linux/bitops.h>
19#include <linux/genhd.h>
20#include <linux/device.h>
21#include <linux/bio.h>
22#include <linux/blkdev.h>
23#include <linux/swap.h>
24#include <linux/swapops.h>
25#include <linux/pm.h>
26#include <linux/slab.h>
27#include <linux/lzo.h>
28#include <linux/vmalloc.h>
29#include <linux/cpumask.h>
30#include <linux/atomic.h>
31#include <linux/kthread.h>
32#include <linux/crc32.h>
33#include <linux/ktime.h>
34
35#include "power.h"
36
37#define HIBERNATE_SIG "S1SUSPEND"
38
39/*
40 * The swap map is a data structure used for keeping track of each page
41 * written to a swap partition. It consists of many swap_map_page
42 * structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
43 * These structures are stored on the swap and linked together with the
44 * help of the .next_swap member.
45 *
46 * The swap map is created during suspend. The swap map pages are
47 * allocated and populated one at a time, so we only need one memory
48 * page to set up the entire structure.
49 *
50 * During resume we pick up all swap_map_page structures into a list.
51 */
52
53#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
54
55/*
56 * Number of free pages that are not high.
57 */
58static inline unsigned long low_free_pages(void)
59{
60 return nr_free_pages() - nr_free_highpages();
61}
62
63/*
64 * Number of pages required to be kept free while writing the image. Always
65 * half of all available low pages before the writing starts.
66 */
67static inline unsigned long reqd_free_pages(void)
68{
69 return low_free_pages() / 2;
70}
71
72struct swap_map_page {
73 sector_t entries[MAP_PAGE_ENTRIES];
74 sector_t next_swap;
75};
76
77struct swap_map_page_list {
78 struct swap_map_page *map;
79 struct swap_map_page_list *next;
80};
81
82/**
83 * The swap_map_handle structure is used for handling swap in
84 * a file-alike way
85 */
86
87struct swap_map_handle {
88 struct swap_map_page *cur;
89 struct swap_map_page_list *maps;
90 sector_t cur_swap;
91 sector_t first_sector;
92 unsigned int k;
93 unsigned long reqd_free_pages;
94 u32 crc32;
95};
96
97struct swsusp_header {
98 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
99 sizeof(u32)];
100 u32 crc32;
101 sector_t image;
102 unsigned int flags; /* Flags to pass to the "boot" kernel */
103 char orig_sig[10];
104 char sig[10];
105} __packed;
106
107static struct swsusp_header *swsusp_header;
108
109/**
110 * The following functions are used for tracing the allocated
111 * swap pages, so that they can be freed in case of an error.
112 */
113
114struct swsusp_extent {
115 struct rb_node node;
116 unsigned long start;
117 unsigned long end;
118};
119
120static struct rb_root swsusp_extents = RB_ROOT;
121
122static int swsusp_extents_insert(unsigned long swap_offset)
123{
124 struct rb_node **new = &(swsusp_extents.rb_node);
125 struct rb_node *parent = NULL;
126 struct swsusp_extent *ext;
127
128 /* Figure out where to put the new node */
129 while (*new) {
130 ext = rb_entry(*new, struct swsusp_extent, node);
131 parent = *new;
132 if (swap_offset < ext->start) {
133 /* Try to merge */
134 if (swap_offset == ext->start - 1) {
135 ext->start--;
136 return 0;
137 }
138 new = &((*new)->rb_left);
139 } else if (swap_offset > ext->end) {
140 /* Try to merge */
141 if (swap_offset == ext->end + 1) {
142 ext->end++;
143 return 0;
144 }
145 new = &((*new)->rb_right);
146 } else {
147 /* It already is in the tree */
148 return -EINVAL;
149 }
150 }
151 /* Add the new node and rebalance the tree. */
152 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
153 if (!ext)
154 return -ENOMEM;
155
156 ext->start = swap_offset;
157 ext->end = swap_offset;
158 rb_link_node(&ext->node, parent, new);
159 rb_insert_color(&ext->node, &swsusp_extents);
160 return 0;
161}
162
163/**
164 * alloc_swapdev_block - allocate a swap page and register that it has
165 * been allocated, so that it can be freed in case of an error.
166 */
167
168sector_t alloc_swapdev_block(int swap)
169{
170 unsigned long offset;
171
172 offset = swp_offset(get_swap_page_of_type(swap));
173 if (offset) {
174 if (swsusp_extents_insert(offset))
175 swap_free(swp_entry(swap, offset));
176 else
177 return swapdev_block(swap, offset);
178 }
179 return 0;
180}
181
182/**
183 * free_all_swap_pages - free swap pages allocated for saving image data.
184 * It also frees the extents used to register which swap entries had been
185 * allocated.
186 */
187
188void free_all_swap_pages(int swap)
189{
190 struct rb_node *node;
191
192 while ((node = swsusp_extents.rb_node)) {
193 struct swsusp_extent *ext;
194 unsigned long offset;
195
196 ext = container_of(node, struct swsusp_extent, node);
197 rb_erase(node, &swsusp_extents);
198 for (offset = ext->start; offset <= ext->end; offset++)
199 swap_free(swp_entry(swap, offset));
200
201 kfree(ext);
202 }
203}
204
205int swsusp_swap_in_use(void)
206{
207 return (swsusp_extents.rb_node != NULL);
208}
209
210/*
211 * General things
212 */
213
214static unsigned short root_swap = 0xffff;
215static struct block_device *hib_resume_bdev;
216
217struct hib_bio_batch {
218 atomic_t count;
219 wait_queue_head_t wait;
220 int error;
221};
222
223static void hib_init_batch(struct hib_bio_batch *hb)
224{
225 atomic_set(&hb->count, 0);
226 init_waitqueue_head(&hb->wait);
227 hb->error = 0;
228}
229
230static void hib_end_io(struct bio *bio)
231{
232 struct hib_bio_batch *hb = bio->bi_private;
233 struct page *page = bio->bi_io_vec[0].bv_page;
234
235 if (bio->bi_error) {
236 printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
237 imajor(bio->bi_bdev->bd_inode),
238 iminor(bio->bi_bdev->bd_inode),
239 (unsigned long long)bio->bi_iter.bi_sector);
240 }
241
242 if (bio_data_dir(bio) == WRITE)
243 put_page(page);
244
245 if (bio->bi_error && !hb->error)
246 hb->error = bio->bi_error;
247 if (atomic_dec_and_test(&hb->count))
248 wake_up(&hb->wait);
249
250 bio_put(bio);
251}
252
253static int hib_submit_io(int rw, pgoff_t page_off, void *addr,
254 struct hib_bio_batch *hb)
255{
256 struct page *page = virt_to_page(addr);
257 struct bio *bio;
258 int error = 0;
259
260 bio = bio_alloc(__GFP_RECLAIM | __GFP_HIGH, 1);
261 bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
262 bio->bi_bdev = hib_resume_bdev;
263
264 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
265 printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
266 (unsigned long long)bio->bi_iter.bi_sector);
267 bio_put(bio);
268 return -EFAULT;
269 }
270
271 if (hb) {
272 bio->bi_end_io = hib_end_io;
273 bio->bi_private = hb;
274 atomic_inc(&hb->count);
275 submit_bio(rw, bio);
276 } else {
277 error = submit_bio_wait(rw, bio);
278 bio_put(bio);
279 }
280
281 return error;
282}
283
284static int hib_wait_io(struct hib_bio_batch *hb)
285{
286 wait_event(hb->wait, atomic_read(&hb->count) == 0);
287 return hb->error;
288}
289
290/*
291 * Saving part
292 */
293
294static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
295{
296 int error;
297
298 hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
299 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
300 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
301 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
302 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
303 swsusp_header->image = handle->first_sector;
304 swsusp_header->flags = flags;
305 if (flags & SF_CRC32_MODE)
306 swsusp_header->crc32 = handle->crc32;
307 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
308 swsusp_header, NULL);
309 } else {
310 printk(KERN_ERR "PM: Swap header not found!\n");
311 error = -ENODEV;
312 }
313 return error;
314}
315
316/**
317 * swsusp_swap_check - check if the resume device is a swap device
318 * and get its index (if so)
319 *
320 * This is called before saving image
321 */
322static int swsusp_swap_check(void)
323{
324 int res;
325
326 res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
327 &hib_resume_bdev);
328 if (res < 0)
329 return res;
330
331 root_swap = res;
332 res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
333 if (res)
334 return res;
335
336 res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
337 if (res < 0)
338 blkdev_put(hib_resume_bdev, FMODE_WRITE);
339
340 return res;
341}
342
343/**
344 * write_page - Write one page to given swap location.
345 * @buf: Address we're writing.
346 * @offset: Offset of the swap page we're writing to.
347 * @hb: bio completion batch
348 */
349
350static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
351{
352 void *src;
353 int ret;
354
355 if (!offset)
356 return -ENOSPC;
357
358 if (hb) {
359 src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN |
360 __GFP_NORETRY);
361 if (src) {
362 copy_page(src, buf);
363 } else {
364 ret = hib_wait_io(hb); /* Free pages */
365 if (ret)
366 return ret;
367 src = (void *)__get_free_page(__GFP_RECLAIM |
368 __GFP_NOWARN |
369 __GFP_NORETRY);
370 if (src) {
371 copy_page(src, buf);
372 } else {
373 WARN_ON_ONCE(1);
374 hb = NULL; /* Go synchronous */
375 src = buf;
376 }
377 }
378 } else {
379 src = buf;
380 }
381 return hib_submit_io(WRITE_SYNC, offset, src, hb);
382}
383
384static void release_swap_writer(struct swap_map_handle *handle)
385{
386 if (handle->cur)
387 free_page((unsigned long)handle->cur);
388 handle->cur = NULL;
389}
390
391static int get_swap_writer(struct swap_map_handle *handle)
392{
393 int ret;
394
395 ret = swsusp_swap_check();
396 if (ret) {
397 if (ret != -ENOSPC)
398 printk(KERN_ERR "PM: Cannot find swap device, try "
399 "swapon -a.\n");
400 return ret;
401 }
402 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
403 if (!handle->cur) {
404 ret = -ENOMEM;
405 goto err_close;
406 }
407 handle->cur_swap = alloc_swapdev_block(root_swap);
408 if (!handle->cur_swap) {
409 ret = -ENOSPC;
410 goto err_rel;
411 }
412 handle->k = 0;
413 handle->reqd_free_pages = reqd_free_pages();
414 handle->first_sector = handle->cur_swap;
415 return 0;
416err_rel:
417 release_swap_writer(handle);
418err_close:
419 swsusp_close(FMODE_WRITE);
420 return ret;
421}
422
423static int swap_write_page(struct swap_map_handle *handle, void *buf,
424 struct hib_bio_batch *hb)
425{
426 int error = 0;
427 sector_t offset;
428
429 if (!handle->cur)
430 return -EINVAL;
431 offset = alloc_swapdev_block(root_swap);
432 error = write_page(buf, offset, hb);
433 if (error)
434 return error;
435 handle->cur->entries[handle->k++] = offset;
436 if (handle->k >= MAP_PAGE_ENTRIES) {
437 offset = alloc_swapdev_block(root_swap);
438 if (!offset)
439 return -ENOSPC;
440 handle->cur->next_swap = offset;
441 error = write_page(handle->cur, handle->cur_swap, hb);
442 if (error)
443 goto out;
444 clear_page(handle->cur);
445 handle->cur_swap = offset;
446 handle->k = 0;
447
448 if (hb && low_free_pages() <= handle->reqd_free_pages) {
449 error = hib_wait_io(hb);
450 if (error)
451 goto out;
452 /*
453 * Recalculate the number of required free pages, to
454 * make sure we never take more than half.
455 */
456 handle->reqd_free_pages = reqd_free_pages();
457 }
458 }
459 out:
460 return error;
461}
462
463static int flush_swap_writer(struct swap_map_handle *handle)
464{
465 if (handle->cur && handle->cur_swap)
466 return write_page(handle->cur, handle->cur_swap, NULL);
467 else
468 return -EINVAL;
469}
470
471static int swap_writer_finish(struct swap_map_handle *handle,
472 unsigned int flags, int error)
473{
474 if (!error) {
475 flush_swap_writer(handle);
476 printk(KERN_INFO "PM: S");
477 error = mark_swapfiles(handle, flags);
478 printk("|\n");
479 }
480
481 if (error)
482 free_all_swap_pages(root_swap);
483 release_swap_writer(handle);
484 swsusp_close(FMODE_WRITE);
485
486 return error;
487}
488
489/* We need to remember how much compressed data we need to read. */
490#define LZO_HEADER sizeof(size_t)
491
492/* Number of pages/bytes we'll compress at one time. */
493#define LZO_UNC_PAGES 32
494#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE)
495
496/* Number of pages/bytes we need for compressed data (worst case). */
497#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
498 LZO_HEADER, PAGE_SIZE)
499#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE)
500
501/* Maximum number of threads for compression/decompression. */
502#define LZO_THREADS 3
503
504/* Minimum/maximum number of pages for read buffering. */
505#define LZO_MIN_RD_PAGES 1024
506#define LZO_MAX_RD_PAGES 8192
507
508
509/**
510 * save_image - save the suspend image data
511 */
512
513static int save_image(struct swap_map_handle *handle,
514 struct snapshot_handle *snapshot,
515 unsigned int nr_to_write)
516{
517 unsigned int m;
518 int ret;
519 int nr_pages;
520 int err2;
521 struct hib_bio_batch hb;
522 ktime_t start;
523 ktime_t stop;
524
525 hib_init_batch(&hb);
526
527 printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
528 nr_to_write);
529 m = nr_to_write / 10;
530 if (!m)
531 m = 1;
532 nr_pages = 0;
533 start = ktime_get();
534 while (1) {
535 ret = snapshot_read_next(snapshot);
536 if (ret <= 0)
537 break;
538 ret = swap_write_page(handle, data_of(*snapshot), &hb);
539 if (ret)
540 break;
541 if (!(nr_pages % m))
542 printk(KERN_INFO "PM: Image saving progress: %3d%%\n",
543 nr_pages / m * 10);
544 nr_pages++;
545 }
546 err2 = hib_wait_io(&hb);
547 stop = ktime_get();
548 if (!ret)
549 ret = err2;
550 if (!ret)
551 printk(KERN_INFO "PM: Image saving done.\n");
552 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
553 return ret;
554}
555
556/**
557 * Structure used for CRC32.
558 */
559struct crc_data {
560 struct task_struct *thr; /* thread */
561 atomic_t ready; /* ready to start flag */
562 atomic_t stop; /* ready to stop flag */
563 unsigned run_threads; /* nr current threads */
564 wait_queue_head_t go; /* start crc update */
565 wait_queue_head_t done; /* crc update done */
566 u32 *crc32; /* points to handle's crc32 */
567 size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */
568 unsigned char *unc[LZO_THREADS]; /* uncompressed data */
569};
570
571/**
572 * CRC32 update function that runs in its own thread.
573 */
574static int crc32_threadfn(void *data)
575{
576 struct crc_data *d = data;
577 unsigned i;
578
579 while (1) {
580 wait_event(d->go, atomic_read(&d->ready) ||
581 kthread_should_stop());
582 if (kthread_should_stop()) {
583 d->thr = NULL;
584 atomic_set(&d->stop, 1);
585 wake_up(&d->done);
586 break;
587 }
588 atomic_set(&d->ready, 0);
589
590 for (i = 0; i < d->run_threads; i++)
591 *d->crc32 = crc32_le(*d->crc32,
592 d->unc[i], *d->unc_len[i]);
593 atomic_set(&d->stop, 1);
594 wake_up(&d->done);
595 }
596 return 0;
597}
598/**
599 * Structure used for LZO data compression.
600 */
601struct cmp_data {
602 struct task_struct *thr; /* thread */
603 atomic_t ready; /* ready to start flag */
604 atomic_t stop; /* ready to stop flag */
605 int ret; /* return code */
606 wait_queue_head_t go; /* start compression */
607 wait_queue_head_t done; /* compression done */
608 size_t unc_len; /* uncompressed length */
609 size_t cmp_len; /* compressed length */
610 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
611 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
612 unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
613};
614
615/**
616 * Compression function that runs in its own thread.
617 */
618static int lzo_compress_threadfn(void *data)
619{
620 struct cmp_data *d = data;
621
622 while (1) {
623 wait_event(d->go, atomic_read(&d->ready) ||
624 kthread_should_stop());
625 if (kthread_should_stop()) {
626 d->thr = NULL;
627 d->ret = -1;
628 atomic_set(&d->stop, 1);
629 wake_up(&d->done);
630 break;
631 }
632 atomic_set(&d->ready, 0);
633
634 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
635 d->cmp + LZO_HEADER, &d->cmp_len,
636 d->wrk);
637 atomic_set(&d->stop, 1);
638 wake_up(&d->done);
639 }
640 return 0;
641}
642
643/**
644 * save_image_lzo - Save the suspend image data compressed with LZO.
645 * @handle: Swap map handle to use for saving the image.
646 * @snapshot: Image to read data from.
647 * @nr_to_write: Number of pages to save.
648 */
649static int save_image_lzo(struct swap_map_handle *handle,
650 struct snapshot_handle *snapshot,
651 unsigned int nr_to_write)
652{
653 unsigned int m;
654 int ret = 0;
655 int nr_pages;
656 int err2;
657 struct hib_bio_batch hb;
658 ktime_t start;
659 ktime_t stop;
660 size_t off;
661 unsigned thr, run_threads, nr_threads;
662 unsigned char *page = NULL;
663 struct cmp_data *data = NULL;
664 struct crc_data *crc = NULL;
665
666 hib_init_batch(&hb);
667
668 /*
669 * We'll limit the number of threads for compression to limit memory
670 * footprint.
671 */
672 nr_threads = num_online_cpus() - 1;
673 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
674
675 page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH);
676 if (!page) {
677 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
678 ret = -ENOMEM;
679 goto out_clean;
680 }
681
682 data = vmalloc(sizeof(*data) * nr_threads);
683 if (!data) {
684 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
685 ret = -ENOMEM;
686 goto out_clean;
687 }
688 for (thr = 0; thr < nr_threads; thr++)
689 memset(&data[thr], 0, offsetof(struct cmp_data, go));
690
691 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
692 if (!crc) {
693 printk(KERN_ERR "PM: Failed to allocate crc\n");
694 ret = -ENOMEM;
695 goto out_clean;
696 }
697 memset(crc, 0, offsetof(struct crc_data, go));
698
699 /*
700 * Start the compression threads.
701 */
702 for (thr = 0; thr < nr_threads; thr++) {
703 init_waitqueue_head(&data[thr].go);
704 init_waitqueue_head(&data[thr].done);
705
706 data[thr].thr = kthread_run(lzo_compress_threadfn,
707 &data[thr],
708 "image_compress/%u", thr);
709 if (IS_ERR(data[thr].thr)) {
710 data[thr].thr = NULL;
711 printk(KERN_ERR
712 "PM: Cannot start compression threads\n");
713 ret = -ENOMEM;
714 goto out_clean;
715 }
716 }
717
718 /*
719 * Start the CRC32 thread.
720 */
721 init_waitqueue_head(&crc->go);
722 init_waitqueue_head(&crc->done);
723
724 handle->crc32 = 0;
725 crc->crc32 = &handle->crc32;
726 for (thr = 0; thr < nr_threads; thr++) {
727 crc->unc[thr] = data[thr].unc;
728 crc->unc_len[thr] = &data[thr].unc_len;
729 }
730
731 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
732 if (IS_ERR(crc->thr)) {
733 crc->thr = NULL;
734 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
735 ret = -ENOMEM;
736 goto out_clean;
737 }
738
739 /*
740 * Adjust the number of required free pages after all allocations have
741 * been done. We don't want to run out of pages when writing.
742 */
743 handle->reqd_free_pages = reqd_free_pages();
744
745 printk(KERN_INFO
746 "PM: Using %u thread(s) for compression.\n"
747 "PM: Compressing and saving image data (%u pages)...\n",
748 nr_threads, nr_to_write);
749 m = nr_to_write / 10;
750 if (!m)
751 m = 1;
752 nr_pages = 0;
753 start = ktime_get();
754 for (;;) {
755 for (thr = 0; thr < nr_threads; thr++) {
756 for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
757 ret = snapshot_read_next(snapshot);
758 if (ret < 0)
759 goto out_finish;
760
761 if (!ret)
762 break;
763
764 memcpy(data[thr].unc + off,
765 data_of(*snapshot), PAGE_SIZE);
766
767 if (!(nr_pages % m))
768 printk(KERN_INFO
769 "PM: Image saving progress: "
770 "%3d%%\n",
771 nr_pages / m * 10);
772 nr_pages++;
773 }
774 if (!off)
775 break;
776
777 data[thr].unc_len = off;
778
779 atomic_set(&data[thr].ready, 1);
780 wake_up(&data[thr].go);
781 }
782
783 if (!thr)
784 break;
785
786 crc->run_threads = thr;
787 atomic_set(&crc->ready, 1);
788 wake_up(&crc->go);
789
790 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
791 wait_event(data[thr].done,
792 atomic_read(&data[thr].stop));
793 atomic_set(&data[thr].stop, 0);
794
795 ret = data[thr].ret;
796
797 if (ret < 0) {
798 printk(KERN_ERR "PM: LZO compression failed\n");
799 goto out_finish;
800 }
801
802 if (unlikely(!data[thr].cmp_len ||
803 data[thr].cmp_len >
804 lzo1x_worst_compress(data[thr].unc_len))) {
805 printk(KERN_ERR
806 "PM: Invalid LZO compressed length\n");
807 ret = -1;
808 goto out_finish;
809 }
810
811 *(size_t *)data[thr].cmp = data[thr].cmp_len;
812
813 /*
814 * Given we are writing one page at a time to disk, we
815 * copy that much from the buffer, although the last
816 * bit will likely be smaller than full page. This is
817 * OK - we saved the length of the compressed data, so
818 * any garbage at the end will be discarded when we
819 * read it.
820 */
821 for (off = 0;
822 off < LZO_HEADER + data[thr].cmp_len;
823 off += PAGE_SIZE) {
824 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
825
826 ret = swap_write_page(handle, page, &hb);
827 if (ret)
828 goto out_finish;
829 }
830 }
831
832 wait_event(crc->done, atomic_read(&crc->stop));
833 atomic_set(&crc->stop, 0);
834 }
835
836out_finish:
837 err2 = hib_wait_io(&hb);
838 stop = ktime_get();
839 if (!ret)
840 ret = err2;
841 if (!ret)
842 printk(KERN_INFO "PM: Image saving done.\n");
843 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
844out_clean:
845 if (crc) {
846 if (crc->thr)
847 kthread_stop(crc->thr);
848 kfree(crc);
849 }
850 if (data) {
851 for (thr = 0; thr < nr_threads; thr++)
852 if (data[thr].thr)
853 kthread_stop(data[thr].thr);
854 vfree(data);
855 }
856 if (page) free_page((unsigned long)page);
857
858 return ret;
859}
860
861/**
862 * enough_swap - Make sure we have enough swap to save the image.
863 *
864 * Returns TRUE or FALSE after checking the total amount of swap
865 * space avaiable from the resume partition.
866 */
867
868static int enough_swap(unsigned int nr_pages, unsigned int flags)
869{
870 unsigned int free_swap = count_swap_pages(root_swap, 1);
871 unsigned int required;
872
873 pr_debug("PM: Free swap pages: %u\n", free_swap);
874
875 required = PAGES_FOR_IO + nr_pages;
876 return free_swap > required;
877}
878
879/**
880 * swsusp_write - Write entire image and metadata.
881 * @flags: flags to pass to the "boot" kernel in the image header
882 *
883 * It is important _NOT_ to umount filesystems at this point. We want
884 * them synced (in case something goes wrong) but we DO not want to mark
885 * filesystem clean: it is not. (And it does not matter, if we resume
886 * correctly, we'll mark system clean, anyway.)
887 */
888
889int swsusp_write(unsigned int flags)
890{
891 struct swap_map_handle handle;
892 struct snapshot_handle snapshot;
893 struct swsusp_info *header;
894 unsigned long pages;
895 int error;
896
897 pages = snapshot_get_image_size();
898 error = get_swap_writer(&handle);
899 if (error) {
900 printk(KERN_ERR "PM: Cannot get swap writer\n");
901 return error;
902 }
903 if (flags & SF_NOCOMPRESS_MODE) {
904 if (!enough_swap(pages, flags)) {
905 printk(KERN_ERR "PM: Not enough free swap\n");
906 error = -ENOSPC;
907 goto out_finish;
908 }
909 }
910 memset(&snapshot, 0, sizeof(struct snapshot_handle));
911 error = snapshot_read_next(&snapshot);
912 if (error < PAGE_SIZE) {
913 if (error >= 0)
914 error = -EFAULT;
915
916 goto out_finish;
917 }
918 header = (struct swsusp_info *)data_of(snapshot);
919 error = swap_write_page(&handle, header, NULL);
920 if (!error) {
921 error = (flags & SF_NOCOMPRESS_MODE) ?
922 save_image(&handle, &snapshot, pages - 1) :
923 save_image_lzo(&handle, &snapshot, pages - 1);
924 }
925out_finish:
926 error = swap_writer_finish(&handle, flags, error);
927 return error;
928}
929
930/**
931 * The following functions allow us to read data using a swap map
932 * in a file-alike way
933 */
934
935static void release_swap_reader(struct swap_map_handle *handle)
936{
937 struct swap_map_page_list *tmp;
938
939 while (handle->maps) {
940 if (handle->maps->map)
941 free_page((unsigned long)handle->maps->map);
942 tmp = handle->maps;
943 handle->maps = handle->maps->next;
944 kfree(tmp);
945 }
946 handle->cur = NULL;
947}
948
949static int get_swap_reader(struct swap_map_handle *handle,
950 unsigned int *flags_p)
951{
952 int error;
953 struct swap_map_page_list *tmp, *last;
954 sector_t offset;
955
956 *flags_p = swsusp_header->flags;
957
958 if (!swsusp_header->image) /* how can this happen? */
959 return -EINVAL;
960
961 handle->cur = NULL;
962 last = handle->maps = NULL;
963 offset = swsusp_header->image;
964 while (offset) {
965 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
966 if (!tmp) {
967 release_swap_reader(handle);
968 return -ENOMEM;
969 }
970 memset(tmp, 0, sizeof(*tmp));
971 if (!handle->maps)
972 handle->maps = tmp;
973 if (last)
974 last->next = tmp;
975 last = tmp;
976
977 tmp->map = (struct swap_map_page *)
978 __get_free_page(__GFP_RECLAIM | __GFP_HIGH);
979 if (!tmp->map) {
980 release_swap_reader(handle);
981 return -ENOMEM;
982 }
983
984 error = hib_submit_io(READ_SYNC, offset, tmp->map, NULL);
985 if (error) {
986 release_swap_reader(handle);
987 return error;
988 }
989 offset = tmp->map->next_swap;
990 }
991 handle->k = 0;
992 handle->cur = handle->maps->map;
993 return 0;
994}
995
996static int swap_read_page(struct swap_map_handle *handle, void *buf,
997 struct hib_bio_batch *hb)
998{
999 sector_t offset;
1000 int error;
1001 struct swap_map_page_list *tmp;
1002
1003 if (!handle->cur)
1004 return -EINVAL;
1005 offset = handle->cur->entries[handle->k];
1006 if (!offset)
1007 return -EFAULT;
1008 error = hib_submit_io(READ_SYNC, offset, buf, hb);
1009 if (error)
1010 return error;
1011 if (++handle->k >= MAP_PAGE_ENTRIES) {
1012 handle->k = 0;
1013 free_page((unsigned long)handle->maps->map);
1014 tmp = handle->maps;
1015 handle->maps = handle->maps->next;
1016 kfree(tmp);
1017 if (!handle->maps)
1018 release_swap_reader(handle);
1019 else
1020 handle->cur = handle->maps->map;
1021 }
1022 return error;
1023}
1024
1025static int swap_reader_finish(struct swap_map_handle *handle)
1026{
1027 release_swap_reader(handle);
1028
1029 return 0;
1030}
1031
1032/**
1033 * load_image - load the image using the swap map handle
1034 * @handle and the snapshot handle @snapshot
1035 * (assume there are @nr_pages pages to load)
1036 */
1037
1038static int load_image(struct swap_map_handle *handle,
1039 struct snapshot_handle *snapshot,
1040 unsigned int nr_to_read)
1041{
1042 unsigned int m;
1043 int ret = 0;
1044 ktime_t start;
1045 ktime_t stop;
1046 struct hib_bio_batch hb;
1047 int err2;
1048 unsigned nr_pages;
1049
1050 hib_init_batch(&hb);
1051
1052 printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
1053 nr_to_read);
1054 m = nr_to_read / 10;
1055 if (!m)
1056 m = 1;
1057 nr_pages = 0;
1058 start = ktime_get();
1059 for ( ; ; ) {
1060 ret = snapshot_write_next(snapshot);
1061 if (ret <= 0)
1062 break;
1063 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1064 if (ret)
1065 break;
1066 if (snapshot->sync_read)
1067 ret = hib_wait_io(&hb);
1068 if (ret)
1069 break;
1070 if (!(nr_pages % m))
1071 printk(KERN_INFO "PM: Image loading progress: %3d%%\n",
1072 nr_pages / m * 10);
1073 nr_pages++;
1074 }
1075 err2 = hib_wait_io(&hb);
1076 stop = ktime_get();
1077 if (!ret)
1078 ret = err2;
1079 if (!ret) {
1080 printk(KERN_INFO "PM: Image loading done.\n");
1081 snapshot_write_finalize(snapshot);
1082 if (!snapshot_image_loaded(snapshot))
1083 ret = -ENODATA;
1084 }
1085 swsusp_show_speed(start, stop, nr_to_read, "Read");
1086 return ret;
1087}
1088
1089/**
1090 * Structure used for LZO data decompression.
1091 */
1092struct dec_data {
1093 struct task_struct *thr; /* thread */
1094 atomic_t ready; /* ready to start flag */
1095 atomic_t stop; /* ready to stop flag */
1096 int ret; /* return code */
1097 wait_queue_head_t go; /* start decompression */
1098 wait_queue_head_t done; /* decompression done */
1099 size_t unc_len; /* uncompressed length */
1100 size_t cmp_len; /* compressed length */
1101 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
1102 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
1103};
1104
1105/**
1106 * Deompression function that runs in its own thread.
1107 */
1108static int lzo_decompress_threadfn(void *data)
1109{
1110 struct dec_data *d = data;
1111
1112 while (1) {
1113 wait_event(d->go, atomic_read(&d->ready) ||
1114 kthread_should_stop());
1115 if (kthread_should_stop()) {
1116 d->thr = NULL;
1117 d->ret = -1;
1118 atomic_set(&d->stop, 1);
1119 wake_up(&d->done);
1120 break;
1121 }
1122 atomic_set(&d->ready, 0);
1123
1124 d->unc_len = LZO_UNC_SIZE;
1125 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1126 d->unc, &d->unc_len);
1127 atomic_set(&d->stop, 1);
1128 wake_up(&d->done);
1129 }
1130 return 0;
1131}
1132
1133/**
1134 * load_image_lzo - Load compressed image data and decompress them with LZO.
1135 * @handle: Swap map handle to use for loading data.
1136 * @snapshot: Image to copy uncompressed data into.
1137 * @nr_to_read: Number of pages to load.
1138 */
1139static int load_image_lzo(struct swap_map_handle *handle,
1140 struct snapshot_handle *snapshot,
1141 unsigned int nr_to_read)
1142{
1143 unsigned int m;
1144 int ret = 0;
1145 int eof = 0;
1146 struct hib_bio_batch hb;
1147 ktime_t start;
1148 ktime_t stop;
1149 unsigned nr_pages;
1150 size_t off;
1151 unsigned i, thr, run_threads, nr_threads;
1152 unsigned ring = 0, pg = 0, ring_size = 0,
1153 have = 0, want, need, asked = 0;
1154 unsigned long read_pages = 0;
1155 unsigned char **page = NULL;
1156 struct dec_data *data = NULL;
1157 struct crc_data *crc = NULL;
1158
1159 hib_init_batch(&hb);
1160
1161 /*
1162 * We'll limit the number of threads for decompression to limit memory
1163 * footprint.
1164 */
1165 nr_threads = num_online_cpus() - 1;
1166 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1167
1168 page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1169 if (!page) {
1170 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1171 ret = -ENOMEM;
1172 goto out_clean;
1173 }
1174
1175 data = vmalloc(sizeof(*data) * nr_threads);
1176 if (!data) {
1177 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1178 ret = -ENOMEM;
1179 goto out_clean;
1180 }
1181 for (thr = 0; thr < nr_threads; thr++)
1182 memset(&data[thr], 0, offsetof(struct dec_data, go));
1183
1184 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1185 if (!crc) {
1186 printk(KERN_ERR "PM: Failed to allocate crc\n");
1187 ret = -ENOMEM;
1188 goto out_clean;
1189 }
1190 memset(crc, 0, offsetof(struct crc_data, go));
1191
1192 /*
1193 * Start the decompression threads.
1194 */
1195 for (thr = 0; thr < nr_threads; thr++) {
1196 init_waitqueue_head(&data[thr].go);
1197 init_waitqueue_head(&data[thr].done);
1198
1199 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1200 &data[thr],
1201 "image_decompress/%u", thr);
1202 if (IS_ERR(data[thr].thr)) {
1203 data[thr].thr = NULL;
1204 printk(KERN_ERR
1205 "PM: Cannot start decompression threads\n");
1206 ret = -ENOMEM;
1207 goto out_clean;
1208 }
1209 }
1210
1211 /*
1212 * Start the CRC32 thread.
1213 */
1214 init_waitqueue_head(&crc->go);
1215 init_waitqueue_head(&crc->done);
1216
1217 handle->crc32 = 0;
1218 crc->crc32 = &handle->crc32;
1219 for (thr = 0; thr < nr_threads; thr++) {
1220 crc->unc[thr] = data[thr].unc;
1221 crc->unc_len[thr] = &data[thr].unc_len;
1222 }
1223
1224 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1225 if (IS_ERR(crc->thr)) {
1226 crc->thr = NULL;
1227 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
1228 ret = -ENOMEM;
1229 goto out_clean;
1230 }
1231
1232 /*
1233 * Set the number of pages for read buffering.
1234 * This is complete guesswork, because we'll only know the real
1235 * picture once prepare_image() is called, which is much later on
1236 * during the image load phase. We'll assume the worst case and
1237 * say that none of the image pages are from high memory.
1238 */
1239 if (low_free_pages() > snapshot_get_image_size())
1240 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1241 read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1242
1243 for (i = 0; i < read_pages; i++) {
1244 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1245 __GFP_RECLAIM | __GFP_HIGH :
1246 __GFP_RECLAIM | __GFP_NOWARN |
1247 __GFP_NORETRY);
1248
1249 if (!page[i]) {
1250 if (i < LZO_CMP_PAGES) {
1251 ring_size = i;
1252 printk(KERN_ERR
1253 "PM: Failed to allocate LZO pages\n");
1254 ret = -ENOMEM;
1255 goto out_clean;
1256 } else {
1257 break;
1258 }
1259 }
1260 }
1261 want = ring_size = i;
1262
1263 printk(KERN_INFO
1264 "PM: Using %u thread(s) for decompression.\n"
1265 "PM: Loading and decompressing image data (%u pages)...\n",
1266 nr_threads, nr_to_read);
1267 m = nr_to_read / 10;
1268 if (!m)
1269 m = 1;
1270 nr_pages = 0;
1271 start = ktime_get();
1272
1273 ret = snapshot_write_next(snapshot);
1274 if (ret <= 0)
1275 goto out_finish;
1276
1277 for(;;) {
1278 for (i = 0; !eof && i < want; i++) {
1279 ret = swap_read_page(handle, page[ring], &hb);
1280 if (ret) {
1281 /*
1282 * On real read error, finish. On end of data,
1283 * set EOF flag and just exit the read loop.
1284 */
1285 if (handle->cur &&
1286 handle->cur->entries[handle->k]) {
1287 goto out_finish;
1288 } else {
1289 eof = 1;
1290 break;
1291 }
1292 }
1293 if (++ring >= ring_size)
1294 ring = 0;
1295 }
1296 asked += i;
1297 want -= i;
1298
1299 /*
1300 * We are out of data, wait for some more.
1301 */
1302 if (!have) {
1303 if (!asked)
1304 break;
1305
1306 ret = hib_wait_io(&hb);
1307 if (ret)
1308 goto out_finish;
1309 have += asked;
1310 asked = 0;
1311 if (eof)
1312 eof = 2;
1313 }
1314
1315 if (crc->run_threads) {
1316 wait_event(crc->done, atomic_read(&crc->stop));
1317 atomic_set(&crc->stop, 0);
1318 crc->run_threads = 0;
1319 }
1320
1321 for (thr = 0; have && thr < nr_threads; thr++) {
1322 data[thr].cmp_len = *(size_t *)page[pg];
1323 if (unlikely(!data[thr].cmp_len ||
1324 data[thr].cmp_len >
1325 lzo1x_worst_compress(LZO_UNC_SIZE))) {
1326 printk(KERN_ERR
1327 "PM: Invalid LZO compressed length\n");
1328 ret = -1;
1329 goto out_finish;
1330 }
1331
1332 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1333 PAGE_SIZE);
1334 if (need > have) {
1335 if (eof > 1) {
1336 ret = -1;
1337 goto out_finish;
1338 }
1339 break;
1340 }
1341
1342 for (off = 0;
1343 off < LZO_HEADER + data[thr].cmp_len;
1344 off += PAGE_SIZE) {
1345 memcpy(data[thr].cmp + off,
1346 page[pg], PAGE_SIZE);
1347 have--;
1348 want++;
1349 if (++pg >= ring_size)
1350 pg = 0;
1351 }
1352
1353 atomic_set(&data[thr].ready, 1);
1354 wake_up(&data[thr].go);
1355 }
1356
1357 /*
1358 * Wait for more data while we are decompressing.
1359 */
1360 if (have < LZO_CMP_PAGES && asked) {
1361 ret = hib_wait_io(&hb);
1362 if (ret)
1363 goto out_finish;
1364 have += asked;
1365 asked = 0;
1366 if (eof)
1367 eof = 2;
1368 }
1369
1370 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1371 wait_event(data[thr].done,
1372 atomic_read(&data[thr].stop));
1373 atomic_set(&data[thr].stop, 0);
1374
1375 ret = data[thr].ret;
1376
1377 if (ret < 0) {
1378 printk(KERN_ERR
1379 "PM: LZO decompression failed\n");
1380 goto out_finish;
1381 }
1382
1383 if (unlikely(!data[thr].unc_len ||
1384 data[thr].unc_len > LZO_UNC_SIZE ||
1385 data[thr].unc_len & (PAGE_SIZE - 1))) {
1386 printk(KERN_ERR
1387 "PM: Invalid LZO uncompressed length\n");
1388 ret = -1;
1389 goto out_finish;
1390 }
1391
1392 for (off = 0;
1393 off < data[thr].unc_len; off += PAGE_SIZE) {
1394 memcpy(data_of(*snapshot),
1395 data[thr].unc + off, PAGE_SIZE);
1396
1397 if (!(nr_pages % m))
1398 printk(KERN_INFO
1399 "PM: Image loading progress: "
1400 "%3d%%\n",
1401 nr_pages / m * 10);
1402 nr_pages++;
1403
1404 ret = snapshot_write_next(snapshot);
1405 if (ret <= 0) {
1406 crc->run_threads = thr + 1;
1407 atomic_set(&crc->ready, 1);
1408 wake_up(&crc->go);
1409 goto out_finish;
1410 }
1411 }
1412 }
1413
1414 crc->run_threads = thr;
1415 atomic_set(&crc->ready, 1);
1416 wake_up(&crc->go);
1417 }
1418
1419out_finish:
1420 if (crc->run_threads) {
1421 wait_event(crc->done, atomic_read(&crc->stop));
1422 atomic_set(&crc->stop, 0);
1423 }
1424 stop = ktime_get();
1425 if (!ret) {
1426 printk(KERN_INFO "PM: Image loading done.\n");
1427 snapshot_write_finalize(snapshot);
1428 if (!snapshot_image_loaded(snapshot))
1429 ret = -ENODATA;
1430 if (!ret) {
1431 if (swsusp_header->flags & SF_CRC32_MODE) {
1432 if(handle->crc32 != swsusp_header->crc32) {
1433 printk(KERN_ERR
1434 "PM: Invalid image CRC32!\n");
1435 ret = -ENODATA;
1436 }
1437 }
1438 }
1439 }
1440 swsusp_show_speed(start, stop, nr_to_read, "Read");
1441out_clean:
1442 for (i = 0; i < ring_size; i++)
1443 free_page((unsigned long)page[i]);
1444 if (crc) {
1445 if (crc->thr)
1446 kthread_stop(crc->thr);
1447 kfree(crc);
1448 }
1449 if (data) {
1450 for (thr = 0; thr < nr_threads; thr++)
1451 if (data[thr].thr)
1452 kthread_stop(data[thr].thr);
1453 vfree(data);
1454 }
1455 vfree(page);
1456
1457 return ret;
1458}
1459
1460/**
1461 * swsusp_read - read the hibernation image.
1462 * @flags_p: flags passed by the "frozen" kernel in the image header should
1463 * be written into this memory location
1464 */
1465
1466int swsusp_read(unsigned int *flags_p)
1467{
1468 int error;
1469 struct swap_map_handle handle;
1470 struct snapshot_handle snapshot;
1471 struct swsusp_info *header;
1472
1473 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1474 error = snapshot_write_next(&snapshot);
1475 if (error < PAGE_SIZE)
1476 return error < 0 ? error : -EFAULT;
1477 header = (struct swsusp_info *)data_of(snapshot);
1478 error = get_swap_reader(&handle, flags_p);
1479 if (error)
1480 goto end;
1481 if (!error)
1482 error = swap_read_page(&handle, header, NULL);
1483 if (!error) {
1484 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1485 load_image(&handle, &snapshot, header->pages - 1) :
1486 load_image_lzo(&handle, &snapshot, header->pages - 1);
1487 }
1488 swap_reader_finish(&handle);
1489end:
1490 if (!error)
1491 pr_debug("PM: Image successfully loaded\n");
1492 else
1493 pr_debug("PM: Error %d resuming\n", error);
1494 return error;
1495}
1496
1497/**
1498 * swsusp_check - Check for swsusp signature in the resume device
1499 */
1500
1501int swsusp_check(void)
1502{
1503 int error;
1504
1505 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1506 FMODE_READ, NULL);
1507 if (!IS_ERR(hib_resume_bdev)) {
1508 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1509 clear_page(swsusp_header);
1510 error = hib_submit_io(READ_SYNC, swsusp_resume_block,
1511 swsusp_header, NULL);
1512 if (error)
1513 goto put;
1514
1515 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1516 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1517 /* Reset swap signature now */
1518 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1519 swsusp_header, NULL);
1520 } else {
1521 error = -EINVAL;
1522 }
1523
1524put:
1525 if (error)
1526 blkdev_put(hib_resume_bdev, FMODE_READ);
1527 else
1528 pr_debug("PM: Image signature found, resuming\n");
1529 } else {
1530 error = PTR_ERR(hib_resume_bdev);
1531 }
1532
1533 if (error)
1534 pr_debug("PM: Image not found (code %d)\n", error);
1535
1536 return error;
1537}
1538
1539/**
1540 * swsusp_close - close swap device.
1541 */
1542
1543void swsusp_close(fmode_t mode)
1544{
1545 if (IS_ERR(hib_resume_bdev)) {
1546 pr_debug("PM: Image device not initialised\n");
1547 return;
1548 }
1549
1550 blkdev_put(hib_resume_bdev, mode);
1551}
1552
1553/**
1554 * swsusp_unmark - Unmark swsusp signature in the resume device
1555 */
1556
1557#ifdef CONFIG_SUSPEND
1558int swsusp_unmark(void)
1559{
1560 int error;
1561
1562 hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
1563 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1564 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1565 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1566 swsusp_header, NULL);
1567 } else {
1568 printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
1569 error = -ENODEV;
1570 }
1571
1572 /*
1573 * We just returned from suspend, we don't need the image any more.
1574 */
1575 free_all_swap_pages(root_swap);
1576
1577 return error;
1578}
1579#endif
1580
1581static int swsusp_header_init(void)
1582{
1583 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1584 if (!swsusp_header)
1585 panic("Could not allocate memory for swsusp_header\n");
1586 return 0;
1587}
1588
1589core_initcall(swsusp_header_init);